How to unsubmit self-assessment

I filed a self-assessment without realising the income threshold had increased. How can I unsubmit my self-assessment?

Hi,
You are able to amend a tax return after you have filed it.
You can find out more information on how to do this here:
Self Assessment tax returns: If you need to change your return
Thank you 

I dont want to amend the return, I want to unsubmit. How can I do that?

Hi ,
 

If you have submitted a Self Assessment tax return and it is incorrect you would not be able to cancel the tax return, but, you can amend the details if incorrect :  Self Assessment tax returns   . Thank you .